Installation for the production of mineral wool and device for spraying a sizing composition, forming part of such an installation

ABSTRACT

An annular device (20) for spraying a sizing composition onto mineral fibres (3) comprises at least one circuit (24, 26) for distributing the sizing composition and at least one spray nozzle (22) in fluid communication with the distribution circuit and arranged on the periphery of the annular spray device in order to spray the sizing composition onto the fibres that pass through the annular spray device defined by an axis of revolution (X-X). According to the invention, the sizing composition is a binder based on biosourced products, and at least one spray nozzle comprises a spray head (36) having a slot (50) through which the biosourced-product-based binder leaves the annular spray device, said slot having a rectangular cross-section such as to form a flat jet of biosourced-product-based binder.

The invention deals with the field of the manufacture of mineral wool,of glass wool type for example, and it relates more particularly to theoperations and the corresponding systems for discharging binder betweenand/or onto the fibres.

Mineral wool manufacturing installations conventionally comprise severalsuccessive stations, including a fiberization station, in which theglass fibre is created, a gluing station, in which the fibres are boundtogether by the addition of a gluing composition, and a crosslinkingstation in which the batt of fibres glued together obtained previouslyis transformed by heating to form the mineral wool.

More specifically, molten glass is deposited into a rotary dish whichforms, in the fiberization station, a centrifuging device, from theoutside of which glass fibres escape to fall towards a conveyor, underthe effect of a stream of air. As the fibres pass in falling towardsthis conveyor, the gluing composition involved in forming the binder issprayed over the passage of the fibres. In order to avoid theevaporation of the gluing composition, a cooling operation can beapplied to the fibres to be glued, through the discharging of a coolantand in particular of water downstream of the gluing operation. The gluedfibres, once cooled, fall onto the conveyor and the dually formed battis then directed towards an oven forming the crosslinking station, inwhich the batt is simultaneously dried and subjected to a specific heattreatment which provokes the polymerization (or “curing”) of the resinof the binder present on the surface of the fibres.

The continuous batt of mineral wool is then intended to be cut to form,for example, panels or rolls of thermal and/or acoustic insulation.

The discharging of binder is controlled at the time of the passage ofthe fibres to be glued. From the prior art, and in particular from thedocument EP1807259, a binder discharge device is known that comprisestwo annular rings bearing spray nozzles and into which the glass fibressuccessively pass. A ring is linked to a tank of binder and each spraynozzle associated with this first ring is configured to receive, on theone hand, a quantity of this binder and, on the other hand, a quantityof compressed air via an independent feed for discharging the binderupon the passage of the glass fibres, and the other ring is linked to atank of coolant and each spray nozzle associated with this second ringis configured to discharge this coolant upon the passage of the glassfibres.

It is known practice to use binders based on phenolic compounds, forwhich the spraying of the binder, the mixing of the binder with thefibres and the passage of these glued fibres into the oven are alleasily controlled by the manufacturers. It is understood that thesetraditionally used binders can pose a problem through the possiblerelease of toxic substances in the form of volatile organic compounds.

The present invention falls within this context and aims to propose anannular device for discharging a gluing composition onto mineral fibres,for example glass fibres, comprising at least one distribution circuitfor said gluing composition and at least one spray nozzle fluidicallyconnected with the distribution circuit and arranged over the perimeterof the annular discharge device for discharging the gluing compositioninto the fibres intended to pass into the annular discharge devicedefined by an axis of revolution. According to the invention, the gluingcomposition is a binder based on biosourced products and at least onespray nozzle comprises a spray head having a slit, through which thebinder based on biosourced products leaves the annular discharge device,with rectangular section so as to form a flat jet of binder based onbiosourced products.

Such a solution allows for the use, as mineral fibre gluing composition,of a binder without phenolic components, and therefore a more ecologicalbinder, based on biosourced products, to form what is known as a “GreenBinder”.

If the use of a green binder is less problematic than that of a binderof phenolic type from an ecological point of view, the inventors havefound that the spraying is made more complicated because the componentsof this green binder generate a binder that is more viscous than thebinder of phenolic type. For that, it is necessary to add water to thegreen binder before it is discharged over the torus of fibres. Thisadditional input of water can pose a problem of evaporation in thestations following the gluing station and according to the invention, ina way complementing the use of a green binder, the use of a spray nozzlethat makes it possible to form a flat jet allows for a good distributionof the binder over the perimeter of the torus of fibres passing into thegluing station and thus avoid a concentration of water on certain zonesof this torus of fibres in order to facilitate the evaporation of thiswater, an overabundance of which is brought for the use of “greenbinder”.

Moreover, such a solution makes it possible to concentrate the jet ofgluing composition to control the orientation thereof and avoid havingthe jets sprayed by the nozzles cross. The inventors have indeeddiscovered that it was beneficial to not allow the jets sprayed by thesenozzles to intersect, such interference potentially generating amodification of the gauge of the drops formed by coalescence.

According to different features of the invention, taken alone or incombination, it will be possible to predict that:

-   -   the at least one spray nozzle is oriented towards the interior        of the annular discharge device with an angle of inclination        determined with respect to a plane of revolution of the annular        discharge device, said angle of inclination lying between 0 and        80°; preferably, this angle of inclination lies between 5° and        80°; a minimum inclination of 5° is advantageous in as much as        it avoids a kick-back of the drops of binder on the torus of        fibres passing into the annular discharge device, a kick-back        which could penalise the subsequent discharging of binder; more        particularly, the angle of inclination can lie between 5° and        70°, a maximum inclination of 70° being advantageous in that it        avoids spraying the binder along the torus of the fibres towards        the conveyor situated under the annular discharge device and in        that it allows the penetration of the binder into the torus of        fibres, while these fibres run at great speed in front of the        annular discharge device; advantageously, the angle of        inclination lies between 5° and 60°;    -   at least two spray nozzles consecutively arranged on the        perimeter of the annular discharge device have an identical        form, being distinguished from one another only by the        inclination of their output channel; it is consequently        understood that, according to the invention, successive spray        nozzles are distinguished essentially by their different        orientation with respect to the plane of revolution of the        annular discharge device, the identical or distinct form, both        in their outer jacket and in the type of jet produced for        example, being a secondary differentiation feature;    -   each spray nozzle being oriented towards the interior of the        annular discharge device with an angle of inclination determined        with respect to a plane of revolution of the annular discharge        device, at least two spray nozzles consecutively arranged on the        perimeter of the annular discharge device are disposed so as to        have an orientation with respect to the plane of revolution of        the annular discharge device with an angle of inclination        different from one another;    -   each nozzle comprises a fixing body secured to an annular tube        delimiting the at least one distribution circuit, and at least        two spray nozzles consecutively arranged on the perimeter of the        annular discharge device having bodies disposed at one and the        same axial level in relation to the axis of revolution of the        annular discharge device;    -   the annular discharge device comprises a plurality of spray        nozzles distributed over the perimeter of the annular discharge        device, each of the spray nozzles comprising a spray head with a        slit with rectangular section;    -   the slit with rectangular section extends mainly in a direction        parallel to the plane of revolution of the device; in other        words, the slit with rectangular section of the at least one        spray nozzle is arranged in such a way that the large side of        the rectangle forming this slit with rectangular section extends        parallel to a plane of revolution of the annular discharge        device;    -   the slit with rectangular section of the at least one spray        nozzle is dimensioned in such a way that the corresponding flat        jet of binder based on biosourced products has a first angular        aperture of between 40° and 120°, in a first direction        corresponding to the large side of said slit; preferably, the        first angular aperture lies between 50° and 70°;    -   the slit with rectangular section of the at least one spray        nozzle is dimensioned in such a way that the corresponding flat        jet of binder based on biosourced products has a second angular        aperture lying between 5° and 40°, in a second direction        corresponding to the small side of said slit; preferably, the        second angular aperture lies between 10° and 30°, and it can        advantageously lie between 15° and 25°;    -   the slit with rectangular section of the at least one spray        nozzle is dimensioned in such a way that the first angular        aperture is at least equal to twice the second angular aperture;        preferably, the value of the first angular aperture is        substantially equal to three times the value of the second        angular aperture; as an example, the second angular aperture can        lie between 16 and 17°, and the first angular aperture can lie        between 50° and 60°;    -   the annular discharge device comprises a plurality of spray        nozzles and each nozzle is adjacent to nozzles whose orientation        with respect to the plane of revolution of the angular discharge        device is different from its own;    -   the nozzles are divided up into at least two sets, between a        first set in which each nozzle is configured so that the        orientation with respect to the plane of revolution of the        annular discharge device takes a first angle of inclination and        a second set in which each nozzle is configured so that the        orientation with respect to the plane of revolution of the        annular discharge device takes a second angle of inclination        that is distinct from the first angle, the spray nozzles being        arranged on the perimeter of the annular discharge device with        an alternation of nozzles of the first set and of nozzles of the        second set; this arrangement contributes to avoiding having the        jets sprayed by the nozzles cross and avoiding a modification of        the gauge of the droplets formed by coalescence; thus, it is        possible according to the invention to dispose nozzles close to        one another, to ensure a coverage of the torus of fibres greater        than 100% and ensure that the torus of fibres is correctly glued        even in the event of failure of one nozzle, while avoiding the        risk, if they all operate simultaneously, of the jets sprayed by        these nozzles not being in the desired form; there is thus        targeted a uniformity of the composition distribution of a        gluing composition onto a torus of glass fibres, since it is        possible to discharge this gluing composition over all the        perimeter of the torus and with a controlled form of the drops        which do not vary according to the spray zone.    -   the nozzles of the first set are configured so that they are        oriented with respect to the plane of revolution of the annual        discharge device with a first angle of inclination lying between        0° and 45°; preferably, the first angle of inclination can be        between 5° and 40°;    -   the nozzles of the second set are configured so that they are        oriented with respect to the plane of revolution of the annular        discharge device with a second angle of inclination lying        between 25° and 80°; preferably, the second angle of inclination        can be between 25° and 60°;    -   the distribution circuit for the binder based on biosourced        products comprises a single feed and a plurality of orifices        connected respectively with a spray nozzle;    -   the annular discharge device comprises two distinct distribution        circuits that are offset along the axis of revolution of the        annular discharge device, the spray nozzles being arranged        between these two distribution circuits so as to be fluidically        connected with each of said distribution circuits;    -   a first distribution circuit is configured to receive the binder        based on biosourced products and a second distribution circuit        is configured to receive compressed air;    -   the first distribution circuit has a mean section of diameter        less than the diameter of the mean section of the second        distribution circuit;    -   the annular discharge device comprises means for controlling the        flow rate of compressed air as a function of the quantity of        gluing composition to be discharged onto the fibres.

The invention relates also to a mineral wool manufacturing installation,comprising fiberization means configured to bring fibres into a gluingstation and notably gluing of these fibres, characterized in that thegluing station comprises only an annular discharge device fordischarging gluing composition according to what has just beendescribed, the annular device being arranged so as to have a plane ofrevolution that is substantially at right angles to the direction ofpassage of the torus of fibres to be glued.

It should be noted that an installation of this type is particularlyadvantageous in that there has been eliminated, in the gluing station,that is to say the station downstream of the fiberization means withrespect to the path of the fibres, a cooling stage. The inventors wereable to note that the fibres passing into such a gluing station with onecooling stage less, are, at the output of the gluing station, that is tosay towards a crosslinking station, in perfect condition for thiscrosslinking operation.

In such an installation, the annular discharge device can be arranged sothat the first distribution circuit, associated with the spraying ofbinder based on biosourced products, is disposed downstream of the pathof the fibres with respect to the second distribution circuit,associated with the compressed air.

The invention relates also to a mineral wool manufacturing method duringwhich at least the following steps are carried out:

-   -   molten glass is brought into a fiberization station,    -   glass fibres are created in this fiberization station, in such a        way that these glass fibres take the form of a bundle of fibres        directed towards a gluing station,    -   in the gluing station, the fibres of the bundle are bound        together by the addition of a gluing composition, the fibres of        the bundle being bound directly upon their entry into the gluing        station without a cooling ring being arranged between the        fiberization station and this gluing operation,    -   and the batt of fibres glued together obtained previously is        transformed by heating to form the mineral wool.

More particularly, the mineral wool manufacturing method can comprise astep of creation of the glass fibres by a centrifuging effect applied tomolten glass, the filaments of glass formed by centrifuging being drawnto form a torus of fibres under the effect of a discharging of a gaseouscurrent at high speed and at sufficiently high temperature.

It can be noted that, in the manufacturing method according to theinvention, the gluing composition is discharged onto the bundle offibres by the discharging of a gluing composition, without the latterbeing associated with a specific cooling step upstream or downstream ofthe discharging of binder in the gluing station. It should be notedthat, in the mineral wool manufacturing method according to theinvention, on the one hand the bundle of fibres formed by the blowing ofthe gaseous current at high temperature receives a discharge of gluingcomposition without it being necessary to form a specific preliminarycooling stage, and on the other hand, the bundle of glued fibres reachesthe crosslinking station without it being necessary to form a specificcooling stage between the gluing station and the crosslinking station.

Other features, details and advantages of the present invention willemerge more clearly on reading the detailed description givenhereinbelow by way of indication, in relation to the different exemplaryembodiments of the invention illustrated in the following figures:

FIG. 1 is a schematic representation of a part of a mineral woolmanufacturing installation, illustrating in particular the gluingstation in which a gluing composition is sprayed onto a torus of fibres;

FIG. 2 is a front view of the gluing device represented schematically inFIG. 1, engaged around a hood of a fiberization station in which thefibres to be glued are obtained;

FIG. 3 is a front view of a half of the gluing device of FIG. 2;

FIG. 4 is a detail view of a gluing device according to a specificembodiment in which the adjacent spray nozzles are inclined differentlyto one another, FIG. 4 illustrating more particularly two spray nozzlesof the gluing device in order to show their different orientation, andthe flat form of the jet of binder as sprayed by these nozzles;

FIG. 4b is a schematic front representation of one of the spray nozzlesof FIG. 4, notably revealing the form of the slit with rectangularsection through which the binder leaves the gluing device;

FIGS. 5 and 6 are cross-sectional views of a spray nozzle according tothe cutting planes V-V and VI-VI represented in FIG. 4;

and FIG. 7 is a partial cross-sectional view of an exemplary embodimentof spray nozzle and of the distribution circuits onto which it is added.

The invention relates to the implementation of specific spray nozzlesfor spraying a particular gluing composition, or binder, onto a torus ofglass fibres, and more particularly it relates to the use of a greenbinder, or binder based on biosourced products, and to the spraying ofthis binder via nozzles that are specific in that they allow a flat jetof this green binder. As will be described hereinbelow, the greenbinder, which requires a consequential input of water, is thus sprayedby avoiding the coalescence of this binder on certain zones of the torusof fibres and thus avoiding any problems of evaporation of the watercontained in the binder in the operations following this spraying.

FIG. 1 shows a part of a mineral wool manufacturing installation 100,and more particularly a glass wool manufacturing installation, and moreparticularly different successive stations participating in the creationof an insulating batt composed of glued glass fibres forming aninsulating material of mineral wool type, for example glass wool. Afirst station, called fiberization station 1, consists in obtainingfibres via a centrifuging dish, downstream of which there is a secondstation, called gluing station 2, in which the gluing of the fibres 3previously obtained by a binder, here a “green binder”, is primarilydone to bind them together.

The glued fibres are placed in a forming station on a conveyor belt 4,which takes them along to an oven forming a crosslinking station 5 andin which they are heated to crosslink the “green binder”.

The conveyor belt 4 is permeable to gases and to water, and it extendsabove suction plenums 6 for the gases such as air, fumes and the excessaqueous compositions from the fiberization process previously described.There is thus formed, on the conveyor belt 4, a batt 7 of glass woolfibres mixed intimately with the gluing composition. The batt 7 isconducted by the conveyor belt 4 to the oven forming the crosslinkingstation 5 for the “green binder”.

It is understood that such an installation line is suited to theproduction of products based on glass wool fibres, as will be described,but it is obviously suited to the production of products based onmineral fibres.

The fiberization station 1 is configured here for the implementation ofa fiberization method based on internal centrifuging. It will beunderstood that any type of centrifuging and of associated centrifugecan be implemented with the teachings hereinbelow given that fibres areobtained at the output of the centrifuge for their future passage intothe gluing station.

As an example illustrated in FIG. 1, the molten glass can be brought asa thread 14 from a melting oven and first of all recovered in acentrifuge 12, to then escape in the form of a multitude ofrotationally-driven filaments. The centrifuge 12 is moreover surroundedby an annular burner 15 which creates, at the peripheral of the wall ofthe centrifuge, a gaseous current at high speed and at a temperaturethat is sufficiently high to draw the glass fibre filaments into theform of a torus 16.

It is understood that the example of fiberization station given above isindicative of and nonlimiting on the invention, and that it will equallybe possible to provide a method of fiberization by internal centrifugingwith a basket and a perforated bottom wall, or with a dish with a solidbottom, given that the molten glass is drawn by centrifuging to thenextend in the form of a torus of fibres 16 into the gluing station.

Moreover, it will be possible to provide other variants nonlimiting onthe invention for this fiberization station, and in particular means asan alternative to or cumulative with the annular burner, and for exampleheating means 18, for example of inductor type, serving to keep theglass and the centrifuge at the right temperature.

The duly created torus of fibres 16 is surrounded by an annular devicefor projecting a gluing composition formed by a “green binder”, theannular discharge device hereinafter being called gluing device 20, ofwhich only two spray nozzles 22 are represented in FIG. 1.

There now follows a more detailed description of the discharge device,or gluing device 20, arranged in the gluing station 2, notably withreference to FIGS. 2 to 7.

The gluing device 20 comprises an annular ring 21, having a general formof revolution about an axis of revolution X-X. The ring 21 comprises twodistinct distribution circuits that are offset by a distance d along theaxis of revolution X-X and a plurality of spray nozzles 22 arrangedbetween these two distribution circuits and configured to ensure afluidic connection with the distribution circuits. Variants relating tothe number of distribution circuits of the ring and/or to thecirculation of fluid in these distribution circuits will be describedhereinbelow.

In the example illustrated, the annular ring comprises in particular afirst annular tube 23 within which a first distribution duct 24 (visiblein FIGS. 5 to 7 in particular) is formed to allow a circulation of agluing composition, as well as a second annular tube 25, which extendsaccording to a plane of revolution, at right angles to the axis ofrevolution X-X of the annular ring 21, and parallel to the plane ofrevolution of the first annular tube 23. Hereinbelow, a plane ofrevolution P of the annular discharge device is defined as being one orother of the planes of revolution as have just been described, or at thevery least a plane parallel thereto.

Inside this second annular tube 25, a second distribution duct 26 (alsovisible in FIGS. 5 to 7) is formed to allow a circulation of compressedair, capable of discharging the gluing composition onto the fibrespassing through the gluing device 20.

The first annular tube 23 has a tubular form, of which the internal walldelimiting the first distribution duct 24, has a section that isconstant, or substantially constant, over all the perimeter of the tube.Substantially constant section is understood to mean a section whichremains the same with a margin of difference less than 5%. As anindicative example, the mean section of the first annular tube can havea diameter D1 of between 10 mm and 30 mm.

The first annular tube 23 comprises a single feed zone 27, in whichthere is added a feed pipe 28 for a gluing composition, linked at itsother end to a tank of this gluing composition, here not represented,and in which water and glue are mixed.

The gluing composition consists here of a binder with low formaldehydecontent, preferably even without formaldehyde, that will hereinafter bequalified as binder based on biosourced products, or “green binder”.This type of binder is at least partially derived from a base ofrenewable raw material, in particular vegetal material, notably of thetype based on hydrogenated or non-hydrogenated sugars. Complementaryelements relating to productions of this “green binder” can be found atthe end of the description, it being noted that the viscosity of thesebiosourced products is such that water has to be used in largequantities to dilute everything and form a binder that can be sprayedthrough the nozzles.

The feed pipe 28, through which the “green binder”, or even binder basedon biosourced products, is brought into the annular discharge device, isarranged parallel to the axis of revolution of the annular distributionring, but it is understood that this feed could be arranged differentlywithout departing from the context of the invention. It should howeverbe noted that, according to a feature of the invention, the “greenbinder” is injected into the first distribution duct of the firstannular tube via a single feed zone, the “green binder” moreover beingintended to circulate over all the perimeter of the first distributionduct.

The first annular tube 23 delimiting the first distribution duct 24 alsocomprises a plurality of outlet orifices 29, (visible in FIGS. 5 to 7 inparticular), regularly distributed over all the perimeter of the firstannular tube. As will be described in more detail hereinbelow, each ofthese outlet orifices emerges on a spray nozzle 22 arranged to befluidically connected with the first distribution duct 24 via thecorresponding outlet orifice.

The result of the above is that the first annular tube 23 is devoted tothe distribution of the “green binder” toward the spray nozzles 22.

Moreover, the second annular tube 25 has a tubular form, of which theinner wall, delimiting the second distribution duct 26, has a sectionthat is constant, or substantially constant, over all the perimeter ofthe tube.

Substantially constant section is understood to mean a section whichremains the same with a margin of difference less than 5%. As anindicative example, the mean section of the second annular tube can havea diameter D2 of between 30 mm and 50 mm.

Like the first annular tube, the second annular tube 25 comprises asingle feed zone 31 in which there is added a feed coupling 31′ for anintake of compressed air.

The compressed air feed coupling 31′ is arranged parallel to the axis ofrevolution of the annular distribution ring and parallel to the feedpipe 28 for “green binder”, but it is understood that this compressedair feed could be arranged differently without departing from thecontext of the invention. It should however be noted that, according toa feature of the invention, the compressed air is injected into thesecond distribution duct of the second annular tube via a single feedzone the compressed air moreover being intended to circulate over allthe perimeter of the second distribution duct.

The second annular tube 25 delimiting the second distribution duct 26also comprises a plurality of outlet orifices 30 (visible in FIGS. 5 to7), regularly distributed over all the perimeter of the second annulartube. Like what has been able to be described for the first annular tube23, each of these outlet orifices emerges on a spray nozzle 22 arrangedto be fluidically connected with the second distribution duct 26 via thecorresponding outlet orifice, each of the spray nozzles 22 of the gluingdevice 20 being fluidically connected on the one hand with the firstdistribution duct 24 and on the other hand with the second distributionduct 26.

The result of the above is that the second annular tube 26 is devoted tothe distribution of compressed air toward the spray nozzles 22.

As can be seen in FIGS. 2 and 3 in particular, this second annular tube25, delimiting the second distribution duct 26 dedicated to thecirculation of compressed air, is disposed above the first annular tube23, delimiting the first distribution duct 24 dedicated to thecirculation of the gluing composition. For the term above to becorrectly understood, reference is made to the position of the gluingdevice in the installation. The second annular tube 25 disposed abovethe first annular tube 23 is disposed as close as possible to thecentrifuging dish from which the fibres drop, such that these fibresforming the torus 16 are required to pass first of all through theannular tube delimiting the duct dedicated to the compressed air.

The diameter of the loop that the first tube forms around the axis ofrevolution of the annular ring is greater than the correspondingdiameter of the second tube, such that these two annular tubes arearranged one above the other with a radial offset r so that the secondannular tube is innermost with respect to the first annular tube. Theresult thereof is an inclined orientation, relative to the axis ofrevolution of the annular ring, of the spray nozzles 22 which aresecured to each of the two annular tubes. As will be describedhereinbelow, different variant embodiments can be provided in which thespray nozzles are fixed onto the annular tubes in such a way that theirangle of inclination with respect to the axis of revolution is constantover all the perimeter of the annular discharge device (notably visiblein FIGS. 2, 3 and 7) or else in such a way that this angle ofinclination varies from one nozzle to the next (notably visible in 4 to6). It is understood that these variants lie within the context of theinvention, provided that the nozzles allow the spraying of a greenbinder via specific fan-jet nozzles.

The first and second annular tubes are configured so that their internalwall respectively delimiting the first and second distribution ductseach has a mean section that differs from one another. In particular,the inner wall of the second tube defines a mean section of diameter D2greater than the diameter D1 of the mean section of the inner wall ofthe second annular tube. The section of passage for the “green binder”is thus smaller than the section of passage for the compressed air. Sucha feature makes it possible to ensure the fact that the first, narrowerdistribution duct, is constantly filled with the binder and that thereis no failure of feed to the spray nozzles. Moreover, the smallerdimensioning of the first distribution duct makes it possible toaccelerate the speed of displacement of the “green binder” in this firstduct and therefore prevent any clogging of the first annular tube.

In the same context, the distinction to be applied to the first annulartube and second annular tube should be noted. As has been specifiedpreviously, these two annular tubes have a constant mean section. Atleast the first annular tube 23 is subjected to a chemical deburringoperation, in order to eliminate the edges at the point of connection ofthe output orifices 29 and of the feed tube on this first annular tube23. In that way, preventing the deposition of biosourced productsforming part of the binder inside the first annular tube is alsotargeted. It is understood that the viscous nature of these componentspresents a risk of seeing them remain attached to any excessively markedroughness inside the annular tube and that the context of application ofthese green binders in the annular discharge device according to theinvention implies taking into account this surface roughness and thedimensioning of the annular tube in which the green binder is requiredto circulate.

The difference in internal diameter of the annular tubes results also ina difference in outer diameter of these tubes such that a larger tube isprovided for the intake of air than for the intake of the gluingcomposition. In the example illustrated, the larger tube is locatedabove the smaller, and fixing flanges, here not represented, for fixingthe ring in the gluing station, can be added in particular on the largertube. It is understood that the tubes could be arranged differentlyrelative to one another without that in any way departing from thecontext of the invention, with, in particular, the air intake tube whichcould be situated below the smaller tube provided for the gluingcomposition.

As illustrated in FIGS. 2 to 7 in particular, the annular tubes 23, 25forming the annular duct 21 are arranged one above the other such thatthe first outlet orifices of the first distribution duct and the secondoutlet orifices of the second distribution duct axially superpose, thatis to say that they are distributed angularly in the same way about thecorresponding axis of revolution of the duct.

In this way, the spray nozzle 22 which fluidically connects a firstoutlet orifice of the first distribution duct with a second outletorifice of the second distribution duct, extends axially, that is to sayin a plane comprising the axis of revolution X-X of the annular ring.

As illustrated in particular in FIGS. 5 to 7, the spray nozzle 22comprises a body 32 which extends between the two annular tubes, aliquid nozzle 34 which extends through this body 32 according to an axisof orientation A-A and at the free end of which is disposed a sprayhead, or air cap, 36, configured to allow the vaporization of the binderbased on biosourced products, or “green binder”, according to a flatjet.

The body 32 has a cylindrical form, here of rectangular section,comprising two internal channels so that the body can receive, on theone hand, the “green binder” coming from the first distribution duct 24via a first outlet orifice 29, and, on the other hand, the compressedair coming from the second distribution duct 26 via a second outletorifice 30. The body 32 is thus defined by an axis of extension Y-Ywhich extends from one annular tube to the other. In the configurationillustrated in FIG. 7, the spray nozzle 22 is configured so that theaxis of extension Y-Y coincides with a straight line passing through thecentre of each of the annular tubes and the result thereof is an angle αbetween the axis of orientation A-A of the liquid nozzle 34 and theplane of revolution P of the annular discharge device that is equal hereto 40°. As illustrated in FIGS. 2 and 3, the set of the spray nozzles 22is arranged so as to have such an angle of inclination, of a value equalto 40°. Generally, the spray nozzles can have a common angle ofinclination, lying between 0 and 80°.

The body 32 of each spray nozzle 22 is welded onto the annular tubes,once its ends are placed facing the outlet orifices formed in each ofthe tubes.

A first face 38 of the body 32 is oriented toward the interior of theannular ring and its axis of revolution X-X and a second face 39 isoriented in the opposite direction. The body comprises, at its centre,transversely to the axis of extension Y-Y of the body, a sheath forreceiving the liquid nozzle 34 emerging at each end on one of the firstand second faces of the body 32. The sheath extends substantially at thecentre of the body, that is to say equidistant from the first annulartube 23 and from the second annular tube 25. The sheath is pierced so asto connect with a first internal channel 42, connected with the firstoutlet orifice 29 and extending parallel to the axis of extension Y-Y ofthe body 32. These internal channels are configured to separately bringthe compressed air and the gluing composition close to the spray head36.

The spray head 36 has a domed form defining a mixing chamber at theoutput of the liquid nozzle 34, in which the compressed air and thegluing composition are mixed to form the drops that are forced to bedischarged via a spray slit 50 formed in the spray head.

It is understood that the spray nozzle 22 is configured to allow afluidic connection between the first distribution duct 24 of the annulartube 23 and/or the second distribution duct 26 of the annular tube 25,and that the spray slit 50, through which the binder based on biosourcedproducts exits from the annular discharge device, is configured todischarge a gluing spray onto the torus of fibres and to disperse thespray over an angular range.

The spray slit 50 is centred on the axis of orientation A-A of the spraynozzle, that is to say on the axis of the hollow rod 46 defining thecirculation duct for the gluing composition inside the body of thevaporiser, and it is understood that the axis of orientation A-A of thespray nozzle defines the main direction of discharge according to whichthe gluing composition will be discharged at the output of the spraynozzle.

As can be seen in FIG. 5 in particular, the spray slit 50 has arectangular section forming a fan nozzle, such that, in the maindirection of discharge, the “green binder” is discharged according to anaperture angle determined by the length of the rectangular section.

The spray head 36 is oriented so that the length of the spray slit 50,that is to say the large side Gc of the rectangle forming this slit, asis notably visible in FIG. 4b , is at right angles to the plane passingthrough the axis of revolution X-X of the annular ring and through theaxis of orientation A-A of the spray nozzle, and parallel to the planeof revolution P of the annular discharge device and therefore of eachannular tube of this device.

The spraying of binder based on biosourced products is, according to theinvention, framed by the form of the spray slit of at least one of thespray nozzles, namely a slit of rectangular section dimensioned in sucha way that the corresponding jet of binder based on biosourced productshas a first angular aperture β₁ lying between 40° and 120°, in a firstdirection corresponding to the large side Gc of said slit 50, and asecond angular aperture β₂lying between 5° and 40°, in a seconddirection corresponding to the small side Pc of said slit 50. The resultthereof is a flat jet, that is to say a jet which extends in a maindirection, here the first direction. It is understood that the valueschosen for the angular apertures must respect this flat jet form andthat, if the second angular aperture is equal to or around 40°, thefirst angular aperture will be at least equal to 80°. In other words,the value of the first angular aperture β₁ is equal to at least twicethe value of the second angular aperture β₂ and it advantageouslycorresponds to a little more than three times this second angularaperture value. As a numeric example, it will be possible to provide asecond angular aperture β₂ with a value in the region of 16° or 17° anda first angular aperture with a value in the region of 51° to 60°.

It is advantageous for the first direction to be parallel to the planeof revolution P of the annular discharge device, that is to say theplane in which each of the annular tubes of the device lies, andtherefore for this first direction to be at right angles to thedirection of displacement of the fibres through the annular dischargedevice 20. Thus, a spraying over a significant angular portion of thetorus of fibres is assured, and the covering by the binder of all of thefibres passing through the annular discharge device is obtained with asmaller number of spray nozzles.

The operation of the gluing device with at least one spray nozzle as hasjust been described is as follows. Appropriate control means make itpossible to control the intake of the “green binder” into the firstdistribution duct via the feed pipe 28. The “green binder” is pushed tocirculate over all the perimeter of the annular tube delimiting thisfirst distribution duct, and to circulate to each of the first orifices29 connected with the spray nozzle 22. The “green binder” entering intothe spray nozzle 22 passes into the liquid nozzle 34 via the sleeve 40and is pushed towards the spray head 36 and the mixing chamber.

Simultaneously, appropriate control means make it possible to controlthe intake of compressed air, at a desired flow rate and pressure, intothe second distribution duct via the feed coupling 31′. The flow rateand the pressure of the air are determined in particular as a functionof the dosage of gluing composition. The compressed air is pushed tocirculate over all the perimeter of the annular tube delimiting thissecond distribution duct, and to circulate to each of the secondorifices connected with the spray nozzle 22. The compressed air enteringinto the spray nozzle 22 is pushed in the circulation ducts 48 at theperiphery of the liquid nozzle 34 toward the spray head 36 and themixing chamber, in which the mix of the compressed air and of the “greenbinder” participates in the vaporization of the binder, the control ofthe air flow rate as a function of the quantity of binder dischargedmaking it possible in particular to act on the size of the drops.

As is illustrated in FIGS. 2 to 6 in particular, the gluing deviceaccording to the invention comprises a plurality of spray nozzles,arranged on the perimeter of the annular ring. These nozzles areannularly distributed regularly over all the perimeter of the ring. Itis understood that, according to the embodiments of the invention, thenumber of nozzles, and therefore the angular separation between twoadjacent nozzles, can vary from one gluing device to another. In FIG. 2,the gluing device comprises a series of sixteen spray nozzles, such thatthe annular separation between two successive nozzles of the series is22.5°.

These nozzles are arranged on one and the same axial level, that is tosay each arranged between the first annular tube and the second annulartube, such that the body of each nozzle is centred on one and the sameplane at right angles to the axis of revolution of the annular ring. Inother words, it can be stated that the spray nozzles are configured sothat their bodies, that is to say their junction with each of theannular tubes, extend to the same height.

There now follows a description of a variant arrangement of the spraynozzles according to the invention, which differs notably from what hasbeen described with reference to FIGS. 2 and 3 through the variableinclination of at least two of these nozzles on the perimeter of theannular ring.

In FIGS. 4, 5 and 6, an exemplary embodiment has been illustrated inwhich all the spray nozzles are of identical design, such that thenozzles differ only by the inclination of their axis of orientation A-A.It will be understood that, without departing from the context of theinvention, the spray nozzles could differ in their design, given that atleast two spray nozzles extending to the same height each haveinclinations different from one another.

According to the invention, at least two spray nozzles consecutivelyarranged on the perimeter of the ring, that is to say two adjacent spraynozzles as illustrated in FIG. 4, are disposed so that the axis oforientation A-A, and therefore its outlet channel, of one of these twonozzles has an angle with respect to the plane of revolution of the ringdifferent from that of the other two nozzles.

In the example illustrated, at least two sets of spray nozzles aredistinguished by their inclination with respect to the plane ofrevolution of the ring. The spray nozzles of a first set 221, like thatvisible in FIG. 6, are inclined so that the axis of orientation A-Aforms, with the plane of revolution of the annular ring, a first angleα1, here equal to 30°. And the spray nozzles of a second set 222, suchas that visible in FIG. 6, are inclined so that the axis of orientationA-A forms, with the plane of revolution of the annular ring, a secondangle α2, here equal to 45°.

It is understood, by virtue of the feature of the invention according towhich two adjacent nozzles have different inclinations, that the nozzlesof each of these two sets are alternated over all the perimeter of theannular ring, such that a nozzle of a given first set 221 of spraynozzles is not adjacent to a nozzle forming part of the same set, thatis to say not adjacent to a nozzle having the same inclination withrespect to the plane of revolution of the annular ring. On theperimeter, there is an alternation of a spray nozzle 22 of a first set221 of nozzles, a spray nozzle 22 of a second set 222 of nozzles, thenonce again a spray nozzle 22 of a first set 221 of nozzles, etc.

FIGS. 5 and 6 illustrate an example according to the invention forproducing the different inclinations from one spray nozzle to another.

In each of the two cases illustrated, the centre C of the sleeve (as isnotably visible in FIG. 7) formed in the body, and the centre of each ofthe annular tubes are aligned. Also, the body is pivoted about thiscentral point defined by the centre C of the sleeve to come to bearagainst the corresponding annular tube in a zone of contact 52 more orless distant from the vertical axis, that is to say the axis parallel tothe axis of revolution of the annular ring and passing through thecentre of this tube. The result thereof is that the centre C of thesheath of each body is substantially in the same position with respectto the annular tubes from one case to the other, without axial offsetrelative to the axis of revolution X-X. In other words, the bodies ofthe spray nozzles having different inclinations are disposed at one andthe same axial level relative to the axis of revolution of the annulardischarge device.

In a first radial cutting plane illustrated in FIG. 5 and correspondingto the cutting plane V-V of FIG. 4, a spray nozzle of a first set 221 ofnozzles has been illustrated. The first outlet orifice of the first tubeand the second outlet orifice are separated from the vertical axisspecific to each annular tube and the result thereof is a firstinclination of the body of the nozzle so that its ends come to overlapthe two outlet orifices. This first inclination is equal to theinclination of angle α1 of the axis or orientation A-A of the spraynozzle of a first set 221 with respect to the plane of revolution, thatis to say, here, equal to 30°.

In a second radial cutting plane illustrated in FIG. 6 and correspondingto the cutting plane VI-VI of FIG. 4, a spray nozzle of a second set 222of nozzles has been illustrated. The first outlet orifice of the firsttube and the second outlet orifice are closer to the vertical axisspecific to each annular tube than they are in the first cutting plane,and the result thereof is a second inclination of the body of the nozzleso that its ends come to overlap the outlet orifices. This secondinclination is equal to the inclination of angle α2 of the axis oforientation A-A of the spray nozzle of the second set 222 with respectto the plane of revolution, that is to say, here, equal to 45°.

It should be noted that a spray nozzle of a first set and a spray nozzleof a second set, and in particular two nozzles concentrically arrangedon the perimeter of the annular discharge device, have an identicalform, as can be illustrated in the figures, and that these nozzles aredistinguished from one another only by the inclination of the bodylinking the two distribution ducts and therefore by the inclination oftheir outlet channel.

As is illustrated in FIG. 1, this difference in orientation of thenozzles of the first set 221 and of the nozzles of the second set 222results in a difference in height of discharge of the jets of binderonto the torus of fibres 16. The binder discharged by the nozzles of thefirst set 221 thus impact the fibres earlier than the binder dischargedby the nozzles of the second set 222. This way, the first spray 201discharged by the nozzle of the first set 221 extends over a plane thatis offset axially with respect to the plane in which extends the secondspray 202 discharged by a nozzle of the second set 222 and the dropsformed in a spray do not meet, or at the very least do so withinacceptable limits, drops formed in an adjacent spray, so as to eliminateor limit a problem of coalescence of drops that could be generated bythe meeting of the sprays. FIG. 4 shows, by way of example, a zone ofaxial overlap ZR, in which drops formed at an orthoradial end 201′ ofthe first spray 201 pass over drops formed at an orthoradial end 202′ ofthe second spray 202. In this zone of overlap, the axial offset alongthe axis of revolution X-X ensures that the drops do not meet and do notrisk being deformed. It is thus possible to arrange two adjacent spraynozzles as close as possible together in as much as they form sets ofnozzles that are distinct, and therefore at distinct orientations, so asto form these zones of overlap without risk of modification of the dropsand so as to be able to ensure a necessary function of redundancy for agluing of all the perimeter of the torus of fibres should one of thespray nozzles malfunction. It can easily be understood, notably byreferring to the illustration of FIG. 4, that, should a spray nozzle ofa first set 221 stop operating, gluing agent could continue to bedischarged in the zone ZR by a neighbouring nozzle of a second set 222,at a different height to that at which said zone ZR could be glued bythe nozzle of the first set 221. This difference in discharge heightgenerated by the differences of inclination of the adjacent nozzleswhich makes it possible to avoid having the size of the drops deliveredby these two adjacent nozzles being modified if they are both in workingorder.

An arrangement according to the invention can be implemented in thedevice described and illustrated previously, and can also beimplemented, without departing from the context of the invention, inother embodiments of devices. As an example, it will be possible toprovide for the device to comprise spray nozzles arranged directly on anannular tube inside which the “green binder” circulates, the air beingadded independently before each nozzle, without it being necessary toprovide an air distribution duct common to each nozzle and thereforespray nozzles arranged between two ducts as they have been describedpreviously. Consequently, such a device is in accordance with theinvention in that it comprises a distribution circuit for the “greenbinder” and a plurality of spray nozzles fluidically connected with thedistribution circuit and distributed over the perimeter of the annulardischarge device to discharge the “green binder” onto the glass fibresintended to pass inside the annular discharge device defined by an axisof revolution, each spray nozzle being configured to discharge a greenbinder in the form of a flat jet.

According to another example, it will be possible to provide for thespray nozzles to be so-called “air-less” nozzles, that is to say nozzlesoperating without the addition of compressed air to produce thedischarge of binder. In this case, a first variant can be provided inwhich the structure of the annular discharge device with the two annulartubes arranged one above the other according to the axis of revolutionand the spray nozzles disposed respectively between these two annulartubes is retained, and in which the second annular tube has only astructural function, without serving as distribution circuit. Only thebinder based on biosourced products circulates in the first distributioncircuit formed by the first annular tube, and no air is sent in thesecond annular tube. It is also possible to provide a second variant inwhich the annular discharge device comprises only one annular tube onwhich the spray nozzles are disposed, it being understood that,according to the invention, the spray nozzles fixed onto this singleannular tube comprise a spray head configured to discharge a flat jet.

According to another example, it will be possible to provide for thenozzles to be divided up into more than two sets, each set being, aspreviously, characterized by nozzles having a specific angle ofinclination. It will be possible to provide a first set defined bynozzles having an inclination a equal to 15°, a second set defined bynozzles having an inclination a equal to 30°, and a third set defined bynozzles having an inclination a equal to 45°. As previously, havingnozzles side-by-side that have the same inclination and whose jet risksbeing disrupted by the adjacent jet, is thus avoided.

There now follows a more detailed description of the binder based onbiosourced products, through different nonlimiting exemplaryembodiments, as it can be injected into the annular discharge deviceaccording to one aspect of the invention for it to be sprayed over atorus of fibres in a mineral wool manufacturing installation, it beingrecalled that this use of binder based on biosourced products is notablymade possible by the implementation of fan jet spray nozzles allowingthe appropriate distribution of this binder over the surface of thefibres.

As a nonlimiting example, the binder based on biosourced products cancontain:

-   -   (a) at least one glucide chosen from among the reducing sugars,        the non-reducing sugars, the hydrogenated sugars and a mix        thereof, and    -   (b) at least one glucide crosslinking agent.        “Glucide crosslinking agent” is understood here to mean a        compound capable of reacting, possibly in the presence of a        catalyst, with the glucides and of forming therewith an at least        partially insoluble three-dimensional network.

Also, the term “glucides” here has a meaning wider than usual, becauseit encompasses not only the glucides in the strict sense, that is to saythe reducing sugars or carbon hydrates of formula C_(n)(H₂O)_(p) havingat least one aldehyde or ketone group (reducing group), but also thehydrogenation products for these carbon hydrates in which aldehyde orketone group has been alcohol-reduced. This term also encompasses thenon-reducing sugars composed of several glucide patterns in which thecarbons carrying semi-acetal hydroxyl are involved in the osidic linksbinding the patterns to one another.

A binder based on biosourced products as has just been presented, namelya gluing composition based on glucides and crosslinking agent,preferably carboxylic polyacids, is described for example in U.S. Pat.No. 8,197,587, WO2010/029266, WO2013/014399, WO2015/181458,WO2012/168619, WO2012/168621, WO2012/072938.

The glucide component can be based on reducing or non-reducing sugars,on hydrogenated sugars free of reducing or non-reducing sugars, or themixtures thereof.

The reducing sugars include simple sugars (monosaccharides) andglucosides (disaccharides, oligosaccharides and polysaccharides). Theexamples of monosaccharides that can be cited are those comprising 3 to8 carbon atoms, preferably the aldoses and advantageously the aldosescontaining 5 to 7 carbon atoms. The aldoses that are particularlypreferred are the natural aldoses (belonging to series D), notably thehexoses such as glucose, mannose and galactose. Lactose or maltose areexamples of disaccharides that can be used as reducing sugar. Thepolysaccharides that can be used for the present invention preferablyhave a molar mass by weight less than 100000, preferably less than 50000, advantageously less than 10 000. Preferably, the polysaccharideincludes at least one pattern chosen from among the abovementionedaldoses, advantageously glucose. Particularly preferred are the reducingpolysaccharides which are composed mostly (more than 50% by weight) ofglucose patterns.

The reducing sugar can notably be a mixture of monosaccharides, ofoligosaccharides and of polysaccharides, notably a dextrin. The dextrinsare compounds that conform to the general formula (C₆H₁₀O₅)_(n). Theyare obtained by the partial hydrolysis of starch. Their dextroseequivalent (DE) is advantageously between 5 and 99, preferably between10 and 80.

The non-reducing sugar is preferably a non-reducing oligoholosideenclosing at most ten glucide patterns. Examples of such non-reducingsugars that can be cited are the diholosides such as trehalose, theisotetrahaloses, saccharose and the isosaccharose (“isosucroses”), thetriholosides such as melezitose, gentianose, raffinose, erlose andumbelliferose, the tetraholosides such as stachyose, and thepentaholosides such as verbascose. Saccharose and trehalose will bepreferred, and even better, saccharose.

“Hydrogenated sugar” is understood in the present invention to mean theset of products resulting from the reduction of a saccharide chosen fromamong the monosaccharides, disaccharides, oligosaccharides andpolysaccharides and from mixers of these products. The hydrogenatedsugar is preferably a product of hydrogenation of a hydrolysate ofstarch (degree of hydrolysis is generally characterized by the dextroseequivalent (DE), lying between 5 and 99, and advantageously between 10and 80). The hydrogenation transforms the sugar or the mix of sugars(hydrolysate of starch) into polyols or alcohols of sugar.

Examples of hydrogenated sugars that can be cited include erythritol,arabitol, xylitol, sorbitol, mannitol, iditol, maltitol, isomaltitol,lactitol, cellobitol, palatinitol, maltotritol and the products ofhydrogenation of starch hydrolysates. Preferably, the hydrogenated sugaror the mix of hydrogenated sugars is composed mostly, that is to saymore than 50% by weight, of maltitol (product of hydrogenation ofmaltose, dimer of glucose resulting from the enzymatic hydrolysis ofstarch).

The component (a), namely the glucide composed of hydrogenated sugarsand/or of reducing and/or non-reducing sugars, advantageously representsfrom 30 to 70% by weight, preferably from 40 to 60% by weight, drymaterials of the gluing composition. These values are understood to bebefore the addition of any additives.

The crosslinking agent, that is to say the component (b), used in thepresent invention is preferably chosen from among the polycarboxylicacids, the salts and anhydrides of polycarboxylic acids, the amines, themetal salts of mineral acids, and the salts of amines and of ammonium ofmineral acids, as well as the mixtures of the abovementioned compounds.

The mineral acids are, for example, sulfuric acid, phosphoric acid,nitric acid and hydrochloric acid. The metal salts can be salts ofalkaline, alkaline earth and transition metals.

The mineral acids and their salts that can be used as crosslinking agentin the present invention are described for example in the applicationsWO2012/168619, WO2012/168621 and WO2012/072938.

In a preferred embodiment, the crosslinking agent comprises apolycarboxylic acid or is a polycarboxylic acid. The polycarboxylic acidcan be a polymer acid (that is to say one obtained by polymerization orcarboxylated monomers) or a monomer acid.

To limit the viscosity of the gluing composition, this polycarboxylicacid advantageously has a mean molar mass with a number less than orequal to 50 000, preferably less than or equal to 10 000 andadvantageously less than or equal to 5000.

Examples of polymer polycarboxylic acids that can be cited include thehomopolymers and copolymers obtained from monomers carrying at least onecarboxylic acid group such as “meth” acrylic acid, crotonic acid,isocrotonic acid, maleic acid, cinnamic acid, 2-methymaleic acid,fumaric acid, itaconic acid, 2-methylitaconic acid,a,b-methyleneglutaric acid and the monomers of unsaturated dicarboxylicacid, such as the maleates and the fumarates of alkyl in C₁-C₁₀. Thecopolymers can also contain one or more vinylic or acrylic monomers suchas vinyl acetate, styrene substituted or not by alkyl, hydroxyl orsulfonyl groupings, or by a halogen atom, (meth)acrylonitrile,(meth)acrylamide, the alkyl (meth)acrylates in C₁-C₁₀, notably themethyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate andisobutyl (meth)acrylate.

In a particularly preferred embodiment, the component (b) is orcomprises monomer polycarboxylic acid. Monomer polycarboxylic acid isunderstood to mean a polycarboxylic acid which does not result from thepolymerization of carboxylated monomers. A monomer carboxylic polyacidtherefore does not include a chain of recurrent patterns.

It can be a dicarboxylic, tricarboxylic or tetracarboxylic acid.

The dicarboxylic acids include, for example, oxalic acid, malonic acid,succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid,azelaic acid, sebacic acid, malic acid, tartric acid, tartronic acid,aspartic acid, glutamic acid, fumaric acid, itaconic acid, maleic acid,traumatic acid, camphoric acid, phthalic acid and its derivatives,notably containing at least one atom of boron or of chlorine,tetrahydrophthalic acid and its derivatives, notably containing at leastone atom of chlorine such as chlorendic acid, isophtalic acid,tetraphthalic acid, mesaconic acid and citraconic acid.

The tricarboxylic acids include, for example, citric acid,tricarballylic acid, 1,2,4-butanetricarboxylic acid, aconitic acid,hemimellitic acid, trimellitic acid and trimesic acid.1,2,3,4-Butanetetracarboxylic acid and pyromellitic acid can for examplebe cited as tetracarboxylic acid.

Citric acid will preferably be used.

The component (b) advantageously represents from 30 to 70% by weight,preferably from 40 to 60% by weight, of dry materials of the gluingcomposition of the present invention. These values are understood to bebefore the addition of any additives.

The ratio by weight of the component (a) to the component (b) preferablylies between 70/30 and 30/70, in particular between 60/40 and 40/60.

The gluing composition can also comprise a catalyst which can be chosenfor example from among the bases and the Lewis acids, such as theargiles, colloidal or non-colloidal silica, the metal oxides, thesulfates of urea, the urea chlorides and the catalysts based onsilicates. An esterification catalyst is preferred.

The catalyst can also be a compound containing phosphorus, for example ahypophosphite of alkaline metal, a phosphite or alkaline metal,polyphosphate of alkaline metal, a hydrogenophosphate of alkaline metal,a phosphoric acid an alkylphosphonic acid. Preferably, the alkalinemetal is sodium or potassium.

The catalyst can also be a compound containing chlorine and/or boron forexample tetrafluoroboric acid or a salt of this acid, notably atetrafluoroborate of alkaline metal such as sodium or potassium, atetrafluoroborate of alkaline-earth metal such as calcium or magnesium,a tetrafluoroborate of zinc and a tetrafluoroborate of ammonium.

Preferably, the catalyst is sodium hypophosphite, sodium phosphite or amixture of these compounds.

The quantity of catalyst introduced into the gluing compositiongenerally represents at most 20% by weight, advantageously from 1 to 10%by weight, and into the total weight of the components (a) and (b).

Generally, the embodiments which are described above are in no waylimiting: it will notably be possible to devise variants of theinvention comprising only a selection of features described that areconsequently isolated by the other features mentioned in this document,if this selection of features is sufficient to confer a technicaladvantage or to differentiate the invention with respect to the state ofthe prior art.

1. Annular discharge device (20) for discharging a gluing compositiononto mineral fibres (3), comprising at least one distribution circuit(24, 26) for distributing said gluing composition and at least one spraynozzle (22) fluidically connected with the distribution circuit andarranged on the perimeter of the annular discharge device fordischarging the gluing composition onto the fibres intended to passinside the annular discharge device defined by an axis of revolution(X-X), characterized in that the gluing composition is a binder based onbiosourced products and in that at least one spray nozzle comprises aspray head (36) having a slit (50), through which the binder based onbiosourced products leaves the annular discharge device, withrectangular section so as to form a flat jet of binder based onbiosourced products.
 2. Annular discharge device for discharging agluing composition according to the preceding claim, characterized inthat the at least one spray nozzle (22, 221, 222) is oriented towardsthe interior of the annular discharge device with an angle ofinclination (α) determined in relation to a plane of revolution (P) ofthe annular discharge device, said angle of inclination (α) lyingbetween 0 and 80°.
 3. Annular discharge device for discharging a gluingcomposition according to the preceding claim, characterized in that,each spray nozzle (22) being oriented towards the interior of theannular discharge device with an angle of inclination (α) determinedwith respect to a plane of revolution (P) of the annular dischargedevice, at least two spray nozzles (22, 221, 222) consecutively arrangedon the perimeter of the annular discharge device are disposed so as tohave an orientation with respect to the plane of revolution (P) of theannular discharge device with an angle of inclination (α) different fromone another.
 4. Annular discharge device for discharging a gluingcomposition according to claims 2 and 3, characterized in that eachspray nozzle (22, 221, 222) is adjacent to nozzles whose orientationwith respect to the plane of revolution (P) of the angular dischargedevice (20) is different from its own.
 5. Annular discharge device fordischarging a gluing composition according to one of the precedingclaims, characterized in that it comprises a plurality of spray nozzles(22, 221, 222) distributed over the perimeter of the annular dischargedevice (20), each of the spray nozzles comprising a spray head (36) witha slit (50) with rectangular section.
 6. Annular discharge device fordischarging a gluing composition according to the preceding claim,characterized in that the slit (50) with rectangular section of the atleast one spray nozzle (22) is arranged so that the large side of therectangle forming this slit extends parallel to a plane of revolution(P) of the annular discharge device.
 7. Annular discharge device fordischarging a gluing composition according to one of claims 5 and 6,characterized in that the slit (50) with rectangular section of the atleast one spray nozzle (22) is dimensioned in such a way that thecorresponding flat jet of binder based on biosourced products has afirst angular aperture (pi) of between 40° and 120°, in a firstdirection corresponding to the large side of said slit (50).
 8. Annulardischarge device for discharging a gluing composition according to oneof claims 5 to 7, characterized in that the slit (50) with rectangularsection of the at least one spray nozzle (22) is dimensioned in such away that the corresponding flat jet of binder based on biosourcedproducts has a second angular aperture (2) of between 5° and 40°, in asecond direction corresponding to the small side of said slit (50). 9.Annular discharge device for discharging a gluing composition accordingto claims 7 and 8, characterized in that the slit (so) with rectangularsection of the at least one spray nozzle (22) is dimensioned in such away that the first angular aperture (β₁) is at least equal to twice thesecond angular aperture (β₂).
 10. Annular discharge device fordischarging a gluing composition according to one of the precedingclaims, characterized in that the distribution circuit (24, 26) fordistributing the binder based on biosourced products comprises a singlefeed (27, 31) and a plurality of orifices (29, 30) connectedrespectively with a spray nozzle (22).
 11. Annular discharge device fordischarging a gluing composition according to one of the precedingclaims, characterized in that it comprises two distinct distributioncircuits (24, 26) that are offset along the axis of revolution (X-X) ofthe annular discharge device (20), the spray nozzles (22) being arrangedbetween these two distribution circuits so as to be fluidicallyconnected with each of said distribution circuits.
 12. Annular dischargedevice for discharging a gluing composition according to the precedingclaim, characterized in that a first distribution circuit (24) isconfigured to receive the binder based on biosourced products and asecond distribution circuit (26) is configured to receive compressedair.
 13. Annular discharge device for discharging a gluing compositionaccording to the preceding claim, characterized in that the firstdistribution circuit (24) has a mean section of a diameter less than thediameter of the mean section of the second distribution circuit (26).14. Mineral wool manufacturing installation (100), comprisingfiberization means configured to bring glass fibres into a gluingstation (2) for these fibres, characterized in that the gluing stationcomprises only a gluing device formed by an annular discharge device(20) for discharging a gluing composition according to one of thepreceding claims, the annular device being arranged so as to have aplane of revolution (P) substantially at right angles to the directionof passage of the torus of fibres to be glued.
 15. Mineral woolmanufacturing installation according to the preceding claim, wherein theannular discharge device (20) conforms to claim 12, characterized inthat the annular discharge device is arranged so that the firstdistribution circuit (24), associated with the spraying of binder basedon biosourced products, is disposed downstream of the path of the fibreswith respect to the second distribution circuit (26), associated withthe compressed air.
 16. Mineral wool manufacturing method during whichat least the following steps are carried out: molten glass is broughtinto a fiberization station, glass fibres are created in thisfiberization station, in such a way that these glass fibres take theform of a bundle of fibres directed towards the gluing station, in thegluing station, the fibres of the bundle are bound together by theaddition of a gluing composition, the fibres of the bundle being bounddirectly upon their entry into the gluing station without a cooling ringbeing arranged in the gluing station, and the batt of fibres gluedtogether obtained previously is transformed by heating to form themineral wool.